An optical diffusible material is used in an optical product such as a lighting cover, an illuminated sign, a transmissive display or a liquid crystal display in order to utilize it effectively by regulating the scattering and transmission of a light from a light source. Basic properties (optical diffusible ability and total transparency) of the optical diffusible material are regulated by adding a filler having optical diffusibility (also referred to hereafter as “optical diffusible filler”) to a transparent base material such as glass, plastic or resin.
Conventionally, inorganic or organic particles have been used as the optical diffusible filler. It is said that the inorganic optical diffusible filler is characterized by being excellent in light resistance and chemical resistance as compared with the organic filler, and silica, alumina, calcium carbonate, barium sulfate, titanium oxide, aluminum hydroxide, glass, talc, mica etc are used (for example, JP-A 2001-188109).